Genetics and Inheritance Final Review

50%

"In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait." If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a homozygous dominant genotype?

100%

"In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait." If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a widow's peak?

25%

"In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait." If two individuals heterozygous for this trait have a child, what is the chance that the child will not be able to roll his tongue?

0%

"In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait." If two individuals homozygous dominant for this trait have a child, what is the chance that the child will not be able to roll his tongue?

one dominant allele, one recessive allele

A couple has a daughter who is color-blind. The mother is not color-blind, but the father is. What is the genotype of the mother for this trait?

100%

A couple is planning to have a child. The female is a carrier for hemophilia; the male does not have hemophilia. What is the chance that a female child will never develop hemophilia?

The father must be BO and the mother must be AO.

A father is blood type B and a mother is blood type A. They have a child with blood type O. What are the genotypes of the father and mother?

trisomy 18

A person born with Edwards syndrome has a genotypic condition identified as

the genes for the phenotype occur on X or Y chromosomes.

A phenotypic trait is considered sex-linked when...

Tay - Sachs.

A recessive allele associated with chromosome 15 causes an enzyme deficiency disease called...

they are lethal during fetal development.

Alterations in chromosome number can occur with any chromosome, but most alterations are not seen in human populations because...

50%

Cystic fibrosis is a genetic disorder that results from the inheritance of two recessive alleles. What is the chance that a child will inherit the disorder if one parent is heterozygous for this gene and one parent has cystic fibrosis?

nondisjunction

Failure of sister chromatids to separate properly is called...

directing the synthesis of protein products that influence but do not directly cause most human behaviors.

Genes represent the set of instructions for the expression of one or more traits human beings and influence human behaviors by....

nondisjunction

Identify the mode of inheritance for Down syndrome.

inheritance of a dominant-lethal allele

Identify the mode of inheritance for Huntington disease.

sex-influenced trait

Identify the mode of inheritance for baldness.

X-linked inheritance

Identify the mode of inheritance for red-green color blindness

a deletion

If a piece of chromosome breaks off during mitosis or meiosis and does not reattach, the event is called...

both heterozygous

If a plant is inherited by complete dominance where homozygous dominant is a red flower color and homozygous recessive is a white flower color, what must the parents' genotypes be if the offspring was 25% white and 75% red?

homozygous

If both alleles of a particular gene are identical, the person is said to be...

increasing insurance costs for healthy individuals based on the results of genetic testing.

In 2008 the U.S. Congress passed GINA, an act that prevents insurance companies from...

multiple alleles and genes contribute to a phenotype.

In polygenic inheritance,

represent a continuous range within the population.

Polygenic traits display phenotypes that

50%

Red-green color blindness is an X-linked recessive disorder. Assume that a mother is a carrier and a father is color-blind. What is the chance that their son will inherit red-green color blindness?

predicting the ratios of possible genotypes of a particular combination of alleles.

The Punnett square is a useful tool for...

all pink.

The flower color in this plant is inherited by incomplete dominance. If a red flower that is homozygous dominant is crossed with a white flower that is homozygous recessive, the color of the offspring flowers will be expected to be...

genes separate from each other during gamete formation so that each sperm and egg receive only one allele from each pair.

The law of segregation states that...

the environment

The trend toward increased height and weight due to improved nutrition in certain human populations is an example of the effect of ________ on phenotypes.

True

True or false. A deletion occurs when a piece of chromosome breaks off and is lost.

False

True or false. A recessive trait that is inherited through complete dominance can occur only if both parents are heterozygous for the trait.

False

True or false. Alleles are alternative versions of chromosomes.

True

True or false. If alleles for the same gene are different in the same person, that individual is heterozygous for the trait.

True

True or false. In incomplete dominance, the phenotype of the heterozygous genotype is an intermediate between the phenotype of either homozygous genotype.

True

True or false. In the human male, genotype and phenotype associated with the genes on the X chromosome are determined by the one X chromosome he inherits from his mother.

False

True or false. Linked genes are not influenced by crossing-over during meiosis.

False

True or false. Mendel's law of independent assortment states that genes separate from each other during gamete formation so that each sperm or egg gets only one unit of each pair.

True

True or false. Polygenic inheritance depends on gene products from multiple genes.

translocation

When a piece of chromosome breaks off and reattaches at another site on the same or another chromosome, this is called...

both sickle-cell anemia and AB blood type

Which of the following human traits is an example of codominance?

sterility and mild mental impairment

Which of the following is characteristic of Klinefelter syndrome?

multiple genes and the environment

Which of the following is most likely involved in the determination of intelligence?

Huntington's disease

Which one of the following genetic disorders is caused by the inheritance of a dominant-lethal allele?

Trisomy -X syndrome

Which one of the following syndromes results in an individual with a nearly normal female phenotype and a tendency to develop mild mental retardation?

incomplete dominance

straight vs. curly vs. wavy hair in humans